Manufacture of endless bands for rubber stamps.



No. 657,500. Patented sept. 4, 1900. a. A. PICKUP.

MANUFACTUBE 0F ENDLESS BANDS FOR RUBBER STAMPS.

(Appl ication led Nov. 20. 1899.)

S- {mmj UNITED STATES GEORGE A. PICKUP, OF

PATENT OFFICE.

BALTIMORE, MARYLAND, AssIGNOR To WILLIAM A. FORCE, on Nnw YORK, N. Y.

MANUFACTURE OF ENDLESS BANDS FOR RUBBER STAMPS.

SPECIFICATION forming part of Letters Patent No. 657,500, dated September 4, 1900.

` Application iled November 20, 1899. Serial No. 737,615. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE A. PICKUP, of the city of Baltimore,in the State of Maryland, have invented certain Improvements in the Manufacture of Endless Bands for Rubber Stamps, of which the following is a specification. Y

This invention relates to certain improvements in the manufacture of endless rubber bands having thereon raised printing characters such as are commonly used in datingstamps where changes in positions of the printing characters with reference to the holder for the bands are required, as will hereinafter fully appear.

The said invention consists in folding a sheet or strip of cloth-lined unvulcanized rubber, with the rubber `side or face outward, and lapping the edges, then placing the folded material, with a separating-sheet of paper, thin metal, or some other suitable material between the two sections thereof to prevent their adhering together, between molds having in their faces the characters to be produced in intaglio, and while so held subjecting the whole to the ordinary vulcanizing process. By this means the lapped edges of the sheet or strip are united in the operation of producing the printing characters in rilievo, the ridge formed by the lapping of the edges being obliterated by the pressure to which the molds are subjected. The product described, if the characters are duplicated longitudinally of the folded sheet, is then cut into strips, each one of whichwonsists of a fiattened endless band having printing characters thereon in relief and adapted foi` application to the holding-block of a stamp.

In the further description of the said invention which follows reference is made to the accompanying drawings, forming a part hereof, and in which- Figure l is a plan view of a sheet of clothlined rubber constituting the blank from which the endless bands are to be made. Fig. 2 shows the blank folded and lapped at its edges and situated between the upper and lower molds ready for introduction into the vulcanizing-press. Fig. 3 is a top or plan view of the folded sheet after its removal from the vulcanizing apparatus and before its severance into bands.

Referring now to the drawings, A is a sheet of cloth-lined unvulcanized rubber of sufficient length and having a width equal to the circumference of the bands to be produced and, in addition, suflicient to form a lap. This sheet is folded upon a separating sheet B, of paper, metal, or other substance, and the edges lapped, when the whole is placed between the molds C, having in their inner faces the characters to be produced on the bauds.

The folded sheet inclosed by the molds is then introduced into the vulcanizing-press (not shown) and subjected to the ordinary process. Upon its removal from the vulcanizing-press the rubber presents the appearance shown in Fig. 3, the printing characters being in relief. The rubber is next cut at the dotted lines x, between the series of raised characters, and each piece will then consist of an endless rubber printing-band suitable for application to the ordinary holding or supporting block of a rubber stamp.

The separating material may be removed from the folded vulcanized rubber sheet either before or after it is cut into bands.

As before stated,the ridge consequent upon lapping the edges of the unvulcanized sheetrubber is obliterated in the vulcanizing operation, and the bands as seen from the outside exhibit an unbroken surface.

Bands made as described have a common thickness throughout and are much superior to those in which the ends are attached in any manner subsequent to the vulcanizing process, for the reason, among others, that they have a uniform length.

I claim as my invention- The` process of making endless rubber printing-bands, which consists in folding a sheet or strip of unvulcanized rubber upon a separating-sheet and lapping the edges, then placing the folded rubber sheet with its separating medium between molds having in their faces printing characters in intaglio, then vulcanizing the folded sheet with the interposed separating medium, and then cutting the sheetinto strips between the raised characters thereon, substantially as specified.

GEORGE A.'PIOKUP.

Witnesses:

WM. T. HOWARD, HARRY E. FEE. 

